Handle for catheter assembly with multifunction wire

ABSTRACT

Multifunction and radial deflection wires ( 66, 64 ) extend from a catheter shaft ( 8 ) and into a handle ( 4 ). The multifunction wire is pulled and pushed longitudinally and is rotated about its axis to change the stiffness of and to laterally deflect the tip portion ( 12 ). A curve size manipulator ( 32 ) on the handle body ( 24 ) moves the multifunction wire longitudinally but does not hinder its rotational movement. Rotation of a lateral deflection manipulator ( 38 ) on the handle causes the proximal end ( 70 ) of the multifunction wire to rotate about its own axis; the free longitudinal movement of the proximal end is unhindered. Any initial corkscrewing or other deflection of the tip portion can be removed at assembly by rotating the proximal end ( 68 ) of the radial deflection wire. The longitudinal movement of the manipulators can be limited by movable stops ( 120 ). The longitudinal positions of the abutment faces ( 126, 128 ) of the stops preferably change according to their longitudinal (distal or proximal) orientation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional application of prior application Ser. No.09/382,352 filed Aug. 25, 1999 which is a divisional of priorapplication Ser. No. 08/920,340, filed Aug. 27,1997 now U.S. Pat. No.5,987,344 which is a continuation-in-part of prior application Ser. No.08/694,363, filed Aug. 8,1996 now U.S. Pat. No. 5,826,576.

This application is related to U.S. Pat. No. 5,545,200, issued Aug. 13,1996 entitled “Steerable Electro-physiology Catheter.” This applicationis a continuation-in-part of U.S. patent application Ser. No.08/694,363, filed Aug. 8, 1996, entitled “Electrophysiology Catheterwith Multi-Function Wire and Method for Making. ” The disclosure of eachis incorporated by reference.

BACKGROUND OF THE INVENTION

Electrophysiology catheters are designed for use in mapping and/orablation of the heart. Electrophysiology catheters typically include anumber of band electrodes mounted to the tip portion of the cathetershaft and a tip electrode at the distal end of the catheter shaft. Toproperly manipulate the electrodes against the target sites within aheart, the tip portion must be flexible and capable of being manipulatedinto a variety of shapes. U.S. patent application Ser. No. 5,487,757,entitled “Multicurved Deflectable Catheter, ” the disclosure of which isincorporated by reference, discloses an electrophysiology catheter inwhich the tip portion can be deflected radially by pulling on amanipulator wire and also defected laterally by rotating a core wirewhich extends into the tip section. In addition to the manipulator andcore wires, this patent discloses the use of an axially slidablestiffener wire, the distal end of which can be located at differentpositions along the tip portion to change the stiffness of the tip, andthus the general size of the curve in the tip.

SUMMARY OF THE INVENTION

The present invention is directed to improvements for a catheterassembly of the type having a multifunction wire. The proximal end ofthe multifunction wire is both rotated about its longitudinal axis andslid longitudinally. This rotational and longitudinal movement occurswhen the user operates lateral deflection and longitudinal positionmanipulators mounted to the handle body.

The catheter assembly also includes a catheter shaft extending from thedistal end of a handle body with the proximal portion of a multifunctionwire extending into the handle body. The multifunction wire is pulledand pushed longitudinally and is rotated about its axis to providemultiple functions for the catheter shaft.

The longitudinal position manipulator is preferably slidably mounted tothe body of the handle for movement between first and secondlongitudinally spaced apart positions. The longitudinal positionmanipulator is connected to the multifunction wire through a rotarycoupling so that movement of the longitudinal position manipulatorcauses longitudinal movement of the multifunction wire but does nothinder the free rotational movement of the proximal portion of themultifunction wire.

The lateral deflection manipulator is preferably rotatably mounted tothe body of the handle. The proximal end of the multifunction wirepreferably has an elongate drive adapter which passes through a hole ina first gear; the first gear is rotatably mounted to the handle body ata fixed position aligned with the lateral defection manipulator. Thelateral deflection manipulator is rotatably coupled to the first gear,and thus to the drive adapter, typically by second and third gears. Thedrive adapter and first gear have interfering torquing surfaces so thatrotation of the lateral deflection manipulator causes the drive adapter,and thus the proximal portion of the multifunction wire, to rotate aboutits own longitudinal axis while not hindering the free longitudinalmovement of the drive adapter through the first gear.

In addition to the multifunction wire, a radial deflection wire, forexample, can also be used with the invention. The proximal end of theradial deflection wire is preferably coupled to a radial deflectionmanipulator in a way which permits the rotary orientation of theproximal end of the radial deflection wire to be adjusted relative tothe handle. This is typically done to remove, during assembly,undesirable twisting, corkscrewing, or other deflection of the tipportion of the catheter shaft. The longitudinal movement of thelongitudinal position manipulator and the radial deflection manipulatorcan be limited by use of movable stops which can be mounted to thehandle body at a range of longitudinal positions. The longitudinal stopscan be configured so that the longitudinal positions of the abutmentfaces of the stops change according to the orientation of the stops.

The multifunction wire preferably extends into the flexible tip portionof the catheter shaft and is freely longitudinally slidable within thetip portion. Torquing force, which creates lateral deflection of theradially deflected tip portion, is preferably transmitted from themultifunction wire to the tip portion by providing both the distal endof the multifunction wire and the multifunction wire lumen within thetip portion with interfering torquing surfaces, such as created when thetwo have generally complementary oblong cross-sectional shapes.

Other features and advantages of the invention will appear from thefollowing description in which the preferred embodiment has been setforth in detail in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified overall view of a catheter assembly madeaccording to the invention;

FIG. 2 is an exploded isometric view of the handle of the catheterassembly of FIG. 1;

FIG. 3 is an enlarged external isometric view of the central portion ofthe upper body part of FIG. 2 from a reverse direction showing a springfinger and an over-rotation stop;

FIG. 4 is an enlarged exploded isometric view of a slider and theproximal end of the radial deflection wire before being secured to theadjustment adapter of FIG. 2;

FIG. 5 is a cross-sectional view of the catheter shaft of FIG. 1 takenalong line 5—5 of FIG. 1;

FIG. 6 is a cross-sectional view of the tip portion of the cathetershaft of FIG. 1 taken along line 6—6 of FIG. 1;

FIG. 7 is an enlarged cross-sectional view taken along line 7—7 of FIG.1;

FIG. 8 is an enlarged side view of a stop of FIG. 2;

FIG. 9 is an enlarged cross-sectional view taken along line 9—9 of FIG.1;

FIG. 10 illustrates the tip portion of the catheter of FIG. 1 afterradial deflection, as shown by the solid line arrow and the solid lineradially-deflected tip portion, and after in-plane lateral deflection,as illustrated by the dashed line arrow and the dashed line radially-and laterally-deflected tip portion.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a catheter assembly 2 including a proximal endassembly or handle 4 from which a catheter 6 extends. Catheter 6includes a catheter shaft 8 having a main, proximal portion 10 and adistal, tip portion 12 joined at a butt joint 14. Tip portion 12 ispreferably more flexible than main portion 10 and has a number ofelectrodes 16 along its length, and typically a tip electrode 18 at thedistal end 20 of catheter shaft 8. Catheter shaft 8 has a proximal end22 mounted to and extending from handle 4.

FIG. 2 illustrates handle 4 in more detail. Handle 4 includes a hollowbody 24 comprising an upper body part 26 and lower body part 28. Handle4 includes a radial deflection manipulator 30 and a curve sizemanipulator 32 both slidably mounted to handle 4 for movement along thelongitudinal length of the handle, that is parallel to arrows 34, 36 ofFIG. 1. Handle 4 also includes a rotatable lateral deflectionmanipulator 38 in the form of a split ring. Manipulator 38 includes afirst split ring portion 40 and a second split ring portion 42. Firstand second portions 40, 42 define an internal gear 43 for purposes to bediscussed below. Second split ring portion 42 has a stop 44 centeredalong its distal end which engages an over-rotation stop 46 formed onupper body part 26, see FIG. 3. Rotation of manipulator 38 is limited tojust under 360°, that is about 180° each way from the position of FIG. 2(when assembled), by the engagement of stops 44, 46 at either end of thetravel.

Upper body part 26 has a pair of annular barriers 48, 50 which keeplateral deflection manipulator 38 properly aligned on hollow body 24.Annular barrier 50 has a neutral alignment projection 52 which alignswith a similar projection 54 on first split ring portion 40 when lateraldeflection manipulator 38 is at its centered or neutral position. Theuser is provided additional tactile and audible indication of thiscentered or neutral alignment of manipulator 38 relative to body 24 bythe engagement of a projection 56 formed on a spring finger 58, thespring finger being a portion of upper body part 26 between annularbarriers 48, 50. Projection 56 engages a recess, not shown, formed onthe inner surface of first split ring portion 40 at a location generallyaligned with projection 54.

Proximal end 22 of catheter shaft 8 extends into a strain relief 60 atthe distal end 62 of body 24. Catheter 3 includes a radial deflectionwire 64 and multifunction wire 66 passing through catheter shaft 8. Theproximal ends 68, 70 of wires 64, 66 extend into hollow body 24. FIG. 4illustrates proximal end 68 of radial deflection wire 64 having asection of hypotube 72 secured to distal end 68. The distal end 74 ofhypotube 72 is flattened for keyed access into an oblong opening 76formed in an adjustment adapter 78. Adjustment adapter 78 has anenlarged, serrated end 80 and a smaller diameter cylindrical end 82sized to fit within a T-slot 84 formed in a slider 86. T-slot 84 issized so that adjustment adapter 78 fits snugly within the T-slotthrough frictional engagement of the adjustment adapter in the T-slot.However, the exposed serrated end 80 of adjustment adapter 76 permitsthe rotary orientation of proximal end 68 of radial deflection wire 64to be adjusted through the use of a small screwdriver or other toolwhich can be used to rotate adjustment adapter 78 within T-slot 84overcoming the frictional resistance which normally prevents suchrotation. This is useful because it permits, at assembly, anycorkscrewing or other undesirable deflection of tip portion 12 to beremoved or at least substantially reduced.

As shown in FIGS. 5 and 6, radial deflection wire 64, which ispreferably coated with a lubricious material such as PTFE, passesthrough a main lumen 88 formed in main portion 10 of catheter shaft 8and then through a radial deflection lumen 90 formed in tip portion 12.Radial deflection wire 64 is preferably secured to tip portion 12 at ornear distal end 20 of catheter shaft 8. As can be seen from thesefigures, multifunction wire 66, thermocouple wires 92 and electrodewires 94 will also pass through main lumen 88. Electrode wires 94 andthermocouple wires 92 pass through an electrode wire lumen 95 within tipportion 12 while the distal end 96 of multifunction wire 66 passesthrough a lateral deflection lumen 98. Lateral deflection lumen 93 issized with an enlarged central region to permit the proximal portion ofmultifunction wire 66 to pass through lumen 98. Otherwise, lumen 98 hasa flattened shape similar to the flattened shape of distal portion 96 sothat the torque transmitting, interfering torquing surfaces 100, 102 ofdistal portion 96 and lateral deflection lumen 98 oppose. Thisarrangement permits distal end 96 of multifunction wire 98 to slidefreely longitudinally within lateral deflection Lumen 98 but permitslateral deflection of tip portion 12 by the rotation or torquing ofmultifunction wire 96.

The size of the curve of tic portion 12 can be adjusted by adjusting howfar distal portion 96 extends into tip portion 12. The farther distalportion 96 extends into tip portion 12, the stiffer the tip portionbecomes and the smaller the radius of curvature when radial deflectionwire 64 is actuated. Typically radial deflection wire 64 is actuated bybeing pulled; in appropriate circumstances radial deflection wire 64 canbe sufficiently stiff so that radial deflection can be achieved byeither pulling or pushing on the radial deflection wire 64. As isconventional, thermocouple wires 92 extend to tip electrode 18 tomonitor the temperature at the tip electrode while electrode wires 94extend to the various electrodes 16, 18.

FIG. 7 illustrates slider 76 supported by lower body part 28. Slider 78has a central recess 104, see FIG. 4, with an enlarged upper regionsized to snap over and slide along a pair of guide rails 106. Aspring-loaded pin 108, see FIG. 2, extends upwardly from a pin housing110 of slider 76, passes through a longitudinally extending slot 112formed in upper body part 26 and engages a blind bore, not shown, formedwithin an interior surface of radial deflection manipulator 30. In thisway, longitudinal movement of radial deflection manipulator 30 causeslike longitudinal movement of slider 76 and thus of the proximal end 68of radial deflection wire 64.

Radial deflection manipulator 30 can be secured at any desired positionalong slot 112. To do so, manipulator 30 includes a serrated ring 114rotatably mounted about a collet assembly 116. Collet assembly 116includes a pair of split rings 118. One or both of serrated ring 114 andsplit rings 118 have cam surfaces so that rotation of serrated ring 114about hollow body 24 causes split rings 118 to be biased against theouter surface of hollow body 24 thus securing manipulator 30 at thedesired longitudinal location.

Longitudinal movement of slider 76 is limited by engagement of pin 108at either end of slot 112. If desired, this amount of longitudinalmovement can be limited in both distal and proximal directions throughthe use of stops 120. Stops 120, see FIGS. 2 and 8, each have anabutment portion 122 and a pair of legs 124. Each abutment portion 122has first and second longitudinally-faces 126, 128. Legs 124 arelongitudinally offset from the longitudinal center of abutment portion122. Lower body part 28 has a series of spaced apart positions 130 alongits length sized to accept legs 124. Each position 130 is spaced apartby, or example, 2.29 mm (0.090 inch). However, the offset nature of legs124 changes where faces 126, 128 are positioned even though legs 124 maybe located at a particular position 130. In the preferred embodiment thelongitudinal position or faces 126, 128 vary by 1.14 mm (0.045 inch)depending upon which face 126, 128 faces in the distal direction. Inthis way the limit of travel of slider 76 can be adjusted in 1.14 mmincrements as opposed to 2.28 mm increments resulting from the 2.28 mmspacing of positions 130 in the preferred embodiment.

FIGS. 2 and 9 illustrate proximal end 70 of multifunction wire 66 havinga hypotube segment 132 secured to the proximal end. The hypotube segment132 has a flattened end 134 which is affixed to an elongate driveadapter 136. The main body 138 (see FIG. 2) of drive adapter 136 has agenerally circular cross section but with upper and lower recesses 140sized to freely slide through a similarly shaped opening 142 formed in afirst drive gear 144. As seen in FIG. 9, each gear 144, 146, 148 isidentical in construction even though only the first drive gear 144needs to have the specialized shaped opening 142. Third drive gear 148engages internal gear 43 and second drive gear 146. Second drive gear146 acts as an idler gear and transmits motion from third drive gear 148to first drive gear 144. Therefore, rotating lateral deflectionmanipulator 38 causes the gear train including internal gear 43 andgears 148, 146, 144 to rotate and thus drive drive adapter 136 about itslongitudinal axis thus rotating multifunction wire 66 about itslongitudinal axis. This rotation of multifunction wire 66 is relativelyfree except where flattened distal portion 96 of multifunction wire 66engages tip portion 12 through interfering torquing surfaces 100, 102.

The proximal end 150 of drive adapter 136 is rotatably coupled to asecond slider 76 a through a rotary coupling 152. See FIGS. 2 and 4.Rotary coupling 152 is clipped to slider 76 a by a pair of clip arms154. Through clip arms 154 and rotary coupling 152, proximal end 150 ofdrive adapter 136, and thus proximal end 70 of multifunction wire 66, isfree to rotate relative to slider 76 a but is not free to movelongitudinally relative to slider 76 a. The longitudinal position ofslider 76 a is determined by the position of a curve size manipulator32, which is substantially identical to radial deflection manipulator30. Curve size manipulator 32 is coupled to slider 76 a by a pin 108 awhich passes through a slot 112 a formed in upper body part 26. Sliders76 and 76 a have specially adapted portions for accommodating connectionto the radial deflection wire 64 and multifunction wire 66. Similarly, apair of stops 120 can be used proximal and distal of slider 76 a tolimit the longitudinal movement of the slider.

During assembly of catheter assembly 2 the limits of movement of sliders76 and 76 a are determined by the placement of stops 120. Undesirablecorkscrewing or other deflection of tip portion 12 can be removed, orsubstancially removed, by rotating adjustment adapter 78 housed withinT-slot 84. After these adjustments have been made, upper and lower bodyparts 26, 28 are secured to one another, typically by ultrasonicwelding. During use tip portion 12 can be moved in the direction ofarrow 156, from the dashed line position of FIG. 10, aligned withlongitudinal axis 158, o the solid line position of FIG. 10 by themovement of radial deflection manipulator 30 in a proximal direction.The size or radius of the curved tip portion 12 of FIG. 10 can bechanged by the longitudinal movement of curved size manipulator 32.Radially deflected tip portion 12 can be deflected laterally, that is inthe direction of arrow 160, by the rotation of lateral deflectionmanipulator 38. In the preferred embodiment, through the use of stops44, 46, lateral deflection manipulator 38 is limited to movement ofabout 180° in each direction from a neutral or start position. However,by virtue of the gear ratios, one revolution of manipulator 38 resultsin four revolutions of first gear 44.

Modification and variation can be made to the disclosed embodimentwithout departing from the subject of the invention as defined in thefollowing claims. For example, instead of gears, friction drive elementscould be used. Also, by appropriately positioning first gear 144adjacent to internal gear 43 of lateral deflection manipulator 38, theneed for second and third gears 146, 148 would be eliminated; while asingle gear could be used to replace gears 146, 148, doing so wouldresult in a reversal of rotary motion between the lateral deflectionmanipulator 38 and multifunction wire 66, which is generally notdesirable. Other drive schemes could be used to rotate multifunctionwire 66; for example, first drive gear 144 could be coupled tomanipulator 38 by a drive chain. In some situations a small electricmotor could be used to rotate the proximal end 70 of multifunction wire66. Also, adjustment adapter 78 could be configured differently; forexample, instead of using serrations at end 80, cylindrical end 82 couldhave a hexagonal extension to permit the rotary orientation of adapter73 to be changed using a wrench or similar tool.

What is claimed is:
 1. A catheter assembly comprising: a proximal endassembly comprising a hollow body; a catheter extending from the body ofthe proximal end assembly, the catheter comprising a catheter shaft,having a proximal end and a tip portion, and a manipulator element,having a distal portion coupled to tip portion and a proximal portionextending from the catheter shaft into the hollow body; the proximal endassembly further comprising: a manipulator movably mounted to the body;a rotary coupler connecting the manipulator and the proximal portion ofthe manipulator element so that movement of the manipulator moves theproximal portion of the manipulator element; and a radial deflectionelement having a proximal end coupled to the rotary coupler; and saidrotary coupler comprising means for adjusting the rotary orientation ofthe proximal end of the radial deflection element relative to the hollowbody; whereby an initial lateral deflection of the tip portion can beremoved.